1. Field of the Invention
The present invention relates to a vehicle wheel hub assembly including a rotatable hub shell rotatable about an axial axis and a stationary axle. The axle includes a control shaft that is axially displaceable relative to the hub shell, including a retaining means to control the axial position of the control shaft relative to the hub shell. Preferably, the control shaft is separate from and coaxial to the axle and preferably the control shaft is rotatable relative to the axle.
2. Discussion of Prior Art
U.S. Pat. No. 6,089,675 describes a vehicle (i.e. bicycle) wheel hub that includes a control shaft that is internally coaxial with an axle. As illustrated in FIGS. 4a-f of this patent, the control shaft is axially displaceable relative to the axle, however, there is no means to control the position of this control shaft with respect to the axle or hub shell. This creates significant inconvenience when attempting to assemble this hub assembly to the dropouts of the frame. The control shaft is biased by a spring requiring that the operator manually position the control shaft in the axially retracted orientation to provide sufficient clearance with the dropouts to permit assembly. To assemble the hub to the dropouts, the operator must continuously to hold the control shaft in its axially retracted position and resist the bias of the spring. Simultaneously, the operator must position and pre-assemble the wheel between the dropouts. Additionally, the operator must simultaneously support and align the bicycle frame to permit this assembly. The task of completing these three manual operations simultaneously is quite difficult and clumsy and requires considerable skill and dexterity on the part of the operator. Most often, the operator will attempt to align the wheel (i.e. the hub) and/or the bicycle (i.e. the dropouts) by some external means during this assembly.
Further, even if the control shaft were not biased by a spring, control shaft would then be free to easily slide axially relative to the axle and would freely flop back and forth depending on the position and movement of the wheel during this assembly. This would provide even less control and predictability on the axial position of the control shaft, adding further difficulty for the operator that is attempting to assemble the wheel to the dropouts.
The difficulty for the operator when attempting to assemble the wheel to the dropouts is again repeated when the operator attempts to subsequently disassemble or remove the wheel from the dropouts.
Accordingly, it is an objective of the present invention to overcome the forgoing disadvantages and provide an improved vehicle wheel hub assembly, particularly as applied to a bicycle wheel.